Fig 2. No differences in renal pathology between male and female Col4a3KO kidney at 8 weeks of age.

(A-C) H&E-stained cortex from WT male (A), KO male (B), and KO female mouse (C). KO males and females showed glomerulosclerosis (circled) to varying degrees, with some glomeruli appearing less affected and almost normal (stars). Tubular changes were characterized by tubular dilatation and tubular atrophy. (D-F) Sirius red-stained cortex from WT male (D), KO male (E), and KO female mouse (F). WT showed a thin delineation of Sirius Red-stained fibers around tubuli, in KO this was variably thickened, especially in the transition zones between outer and inner stripes of the outer medulla and between outer medulla and cortex. (G) Nephropathy score assessed in H&E- and PAS-stained sections and quantitative analysis of Sirius Red positive interstitial fibrosis demonstrated significantly increased nephropathy and interstitial fibrosis in KO mice compared to WT littermates of the same sex with no differences between female and male mice. (H) Morphometric analysis of F4/80-positive macrophages and α-SMA-positive myofibroblasts showed significant increase of macrophages infiltrates and myofibroblasts deposition in both male and female KO kidney, compared to WT littermate controls of the same sex. The degree of changes was comparable in animals of both sexes with the exception of the F4/80-positive macrophage area being about two-fold higher in female than in male KO mice. (I) Real-time PCR analysis of Col3A1, F4/80 and Thy-1 mRNA showed marked upregulation in the expression of these genes in both male and female KO kidney, compared to WT littermate controls of the same sex. The magnitude of changes was comparable in animals of both sexes. Unpaired t-test was used for the comparison between WT and KO mice of same sexes. *: significance vs WT males; #: significance vs WT females. (G) n = 5 mice per group. (H, I) n = 3 to 8 mice per group. Scale bar 100 μm.